dcc_template: Create the strict bilingual DCC Excel template
Description
Writes a protected version-1.0 workbook for survey staff. Machine
headers and workbook structure are locked; yellow input cells remain editable.
Sheet protection has no password and prevents accidental edits only.
Usage
dcc_template(path, language = "zh-CN")
Value
The normalized destination path, invisibly.
Arguments
path
Destination .xlsx path. Required and never defaulted: the
caller chooses every location DCC writes to. Existing files are never
overwritten.
language
Primary instruction language, "zh-CN" or "en";
both languages remain visible in the workbook.